Rapid and sensitive spectrophotometric determination of cerium(IV) with 2,4-dihydroxy benzophenone benzoic hydrazone

A simple and sensitive spectrophotometric method for the determination of cerium(IV) in an aqueous medium is reported. The metal ion formed a 1:1 orange-red coloured complex with 2,4-dihydroxy benzophenone benzoic hydrazone (DHBPBH) at pH 10.0 showing an absorption maximum at 400 nm. The molar absorptivity and Sandell's sensitivity of the method are found to be 2.0 x 10(4)1/mol/cm and 0.007 mug/cm(2), respectively. Beer's law is obeyed in the range 0.7-7.0 mug/ml. Titanium, vanadium and molybdenum do not interfere. The extent of interferences by other ions is presented. The method is applied for the determination of cerium in simulated rock samples.